Neurochemists Identifying a Molecule of Panic
A panic attack is an anxiety disorder severe, where mental and physical symptoms seem to feed each other: heart palpitations, difficulty breathing, sweating, dizziness, and combine with a feeling of loss of self control, printing to be dying. If the biological and psychological origins of these crises are often difficult to unravel, it has been shown to be induced, both in humans and in animals by sodium lactate or inhalation of CO2. Drugs are available to the curb, but they are not without disadvantages (risk of dependency). A new study illustrates the role of this hormone in anxiety disorders, may open new therapeutic avenues.
A Swedish-US team has indeed found that certain molecules that inhibit the orexin (also called “hypocretin) could reduce panic behavior observed in rats selected to present these anxiety disorders. Philip Johnson (Indiana University) and colleagues also showed that activation of neurons that synthesize orexin is necessary for the onset of panic in these rats. Finally, they found that patients prone to anxiety panic showed concentrations of orexin in the cerebrospinal fluid higher than in a control group.
The orexin has been widely studied for its role in the awakening and its disorders: some dogs with narcolepsy have mutations of orexin receptors, while humans, the molecule is stimulating these receptors is lacking. Recently, a team led by Jian-Sheng Lin (Inserm Unit 628, Université Claude Bernard, Lyon) showed that mice manipulated to express not the orexin directly entered REM sleep and catalepsy. Regarding panic “Correlation is not causation”, Said Mr. Lin, who wonders whether orexin antagonists used by his colleagues simply do not cause drowsiness in animals.
“Instead, the treated rats and show more social interactions and increased exploratory behavior, which goes against the assumption of sedation”, Write Philip Johnson and colleagues. Antoine Pelissolo (Hospital de la Pitie-Salpetriere) said their study “preliminary, but serious, in an area where the tracks are quite limited therapeutic”.